Rhythm Heaven Groove

Base game 1.0.0 (v0), SDK 21.4.0, the newest SDK so far. Nintendo's own 2D engine on NVN; audio is the SDK's AudioRenderer (sound/sm/**/*.cwv). Modules main and sdk. Plays on the iPhone, handheld with Boost.

What it needs

Rendering

One BNSH, shader/shader_NX.bnsh (2 vertex and 33 pixel shaders, all 2D), with Mario's binding layout (every binding decodes). No packaged textures: each texture file (graph/**/*.tex, raw BC7 or linear R8 with its description in the .spr beside it) is read into memory and gets a memory pool the CPU cannot access.

• Resolved: black screen, every sprite and glyph in place under DM_NVN_HILITE. The sprite shader (40adb3021c79b155) computes texture × colour multiply + colour add and discards a fragment whose alpha is 0. The uniform buffer was right (a CBDUMP: multiply 1, add 0), so every texture read 0. The game makes a CPU_NO_ACCESS | GPU_CACHED pool (flags 0x21) on the memory it read each texture file into: 245 pools by the first screens, each holding one texture at offset 0, 17 block-linear BC7 (flag IMAGE, no packaged layout) and 228 linear R8 (IMAGE | LINEAR). NVN keeps what a pool's storage held at nvnMemoryPoolInitialize as its content, but the host uploaded from guest memory only packaged, WriteTexels or flushed textures, and made a linear texture on its pool's buffer only in a pool the CPU can see. Now a new texture in a CPU_NO_ACCESS pool whose storage holds data starts with that content, uploaded once (tex_init_fill in nvn_mtl.m); it stays a GPU texture that can be rendered into, with no re-upload on page writes. A linear one is made on the pool's buffer in any pool (tex_linear). Left out: storage of zeros, COMPRESSIBLE textures (render targets here, in their own 0xa1 pools; their memory means nothing without the compression tags), multisample, depth / stencil and sparse ones. Found by a census of every texture's pool flags, flags, format and whether its storage held data at creation (a temporary line under DM_NVN_LOG).
• Resolved: the latency calibration's beat numbers torn and its background in blue steps. Two BC7 textures without a packaged layout were read with the wrong block height. A dump of the guest bytes deswizzled in Python with 1 to 16 GOBs and decoded with texture2ddecoder shows the right one by eye; a smoothness score does not, because a block height too tall reads padding and looks smooth. Truncating height in blocks × 1.5 / 8, as MacNativeGames found, matches every size checked by eye: 672×160 and 1232×160 (40 block rows: 4 GOBs, where rounding up gives 8), and 112×112 (4), 288×208 (8) and 880×432 (16), where both roundings agree and floor(rows / 8), the other rule that fits 40 rows, does not. nvn_tex.c now uses it for every game (pick_tile(ah * 3 / 16)).

Audio

• Resolved: no sound; red audren: command 0 in the command list is malformed (first word 0x181901 size 0). SDK 21's DSP command header has no magic: +0x00 enabled (bit 0), +0x01 command ID, +0x02 size (s16), +0x04 estimated time, +0x08 node ID (CommandListProcessor::Process, sdk+0x24fd50), and every command body moved 8 bytes forward. DeviceSink is still ID 0x14 but 0x140 bytes: input count +0x128, input indices +0x12c, upsample buffer +0x120 (written at sdk+0x23a7b0). AudioRenderSystem keeps SDK 20's offsets (update lock +0x2d0). capture (hle_audren.c) tries this layout when neither magic walk works, bounded by the generated list's length; its first lists hold 4 commands or fewer, so the layout is now chosen on the first non-empty list.

Services

• Resolved: abort in nn::sm::Initialize under nn::pl::sharedresource::GetPlatformSharedResourceManager, first thing in nnMain. The game asks for every shared font at once with pl::GetSharedFont(int *, SharedFontData *, int, LanguageCode) (sdk+0x40f270), not by type. SharedFontData is 0x18 bytes {u32 type, address, size}; the SDK adds the pl service's offsets, which point past each font's 8-byte BFTTF header, to the shared memory base, and the game hands each address straight to ScalableFontEngine::LoadFont (main+0x501ff0). The hook returns the six types in order with the stand-in TTFs past the header, whatever the profile's shared_font (hle_sdk16.c).
• Resolved: SIGSEGV in vi::GetDefaultDisplayPanelIdentifier (main+0xa9a4, before the window). The SDK's version calls through the vi service object the host never made. The game reads a u32 kind and, from kind 2, 0x14 more bytes; anything else makes it use zeros. The host answers an all-zero identifier (hle_vi.c).

Input

• Not a host bug: the TV latency calibration ("press A when you hear the fourth beat") ignores A. Docked, the first boot runs it (scene script main+0x4c0820). It starts listening only 0x3c0 frames (16 s) after the prompt, through the active controller (main+0x22b0 id 0x3ed, virtual button 4 = A), and passes when about ten presses keep a steady offset within −5 to +13 frames of the cue (evaluation main+0x2948c0; offset = cue ticks at +0x34 / about 17 ticks per frame, about 480 per beat). Scripted presses at fixed seconds drift off the beat; use frame-timed DM_KEYS at the bar period (117.12 frames at its 123 BPM) and read each press's offset with DM_PROBE=main:2951f0@34. A passed calibration is saved per TV panel identity (the host's all-zero one included) and not asked again.
• Current: the profile plays it handheld with Boost, which skips the TV setup and keeps the 1080p draw size.
• The iOS app starts it in the 2D gamepad layout.

Files

• romfs_marker is sound/sm/showtime/n_virus_very_hard.cwv.

Found on this game

General host changes first needed here; each applies to every game:

• Initial content of CPU_NO_ACCESS pools (tex_init_fill) and linear textures in any pool (tex_linear): A pool's storage at creation is its textures' content, Linear textures in CPU-visible pools.
• Truncated automatic block height (pick_tile(ah * 3 / 16) in nvn_tex.c): Automatic block height truncates.
• SDK 21's DSP command list without magic (capture in hle_audren.c), pl::GetSharedFont for every font at once (hle_sdk16.c) and vi::GetDefaultDisplayPanelIdentifier (hle_vi.c): SDK 21 DSP command header without a magic, Shared fonts requested all at once, Default display panel identifier.
• perf_mode (Boost whatever the operation mode, hle_oe.c): dm/games/README.md, Keys.

Open

• game.tsv still describes the game as "In bring-up" (on the Mac it plays from boot through the setup and its TV latency calibration into the first rhythm game, Hoop Trundling, with sound), while AGENTS.md lists it as playable on the iPhone.